In the prior art, we know the document FR2666777 which describes a telescopic nozzle system for a motor vehicle. This nozzle consists of an actuator containing a window washing liquid under pressure which exerts a thrust on a piston that is connected to the tip of the nozzle and rises so as to position it opposite the windshield. The window washing liquid circulates in a passage that goes through the piston and pushes a ball which closes an opening, and then penetrates into the head of the nozzle so as to be projected against the windshield. In this device, a conventional non-return valve is placed in the conduit of the rod of the piston in order to ensure the lifting of the tip of the nozzle and to establish a connection between the washing liquid supply pipes, in order to ensure the spraying of the washing liquid against the surface to be cleaned.